Answer:
Physical quantity is a physical property of an object or material that can be expressed by magnitude and unit.
The derived physical quantities are the type of physical quantities which can be expressed or defined by other physical quantities, called the base quantities. Example: Area, Volume, Velocity
Area- SI Unit: m², U.S. Customary unit: acre
Volume- SI Unit: m³, U.S. Customary unit: cubic inch
Velocity- SI Unit: m/s, U.S. Customary unit: ft/s
Answer:
Very few
Most open clusters form with at least 100 stars
Brainly, please.
The rays of light coming from the Sun are parallel to each other, so when they are reflected by the concave piece of glass (which acts as a concave mirror) they converge into the focus of the mirror, which is

The radius of curvature of a concave mirror is twice its focal length, so in this case it is:
·The acceleration of gravity is proportional to
1 / (the square of the distance from the center) .
When we're on the surface, we're 1 radius from the center of the Earth,
and the acceleration of gravity is 9.8 m/s² .
The boy's weight = (mass) · (gravity) = (50kg) · (9.8 m/s²)
= 490 newtons .
At the distance of 5 radii from the center (4 radii altitude from the surface),
the acceleration of gravity is
(9.8 m/s²) · (1/5)² = 0.39 m/s² .
The boy's weight is (mass) · (gravity) = (50kg) · (0.39 m/s²)
= 19.6 newtons .
Just as we expected, his weight at that distance is
(19.6 / 490) = 0.04 = 1/25 = 1/5² of his weight on the surface.
Answer:
The magnetic field strength of an electromagnet is therefore determined by the ampere turns of the coil with the more turns of wire in the coil the greater will be the strength of the magnetic field.
Explanation: